TULSA, Okla. (AP) _ A campaign to keep Tulsa's air clean didn't keep the city from surpassing air quality standards Wednesday.
An ozone monitoring station west of the city recorded a moderately unhealthy level of ozone of .085 parts per million over an 8-hour average Wednesday, officials said. It was the first violation of the summer.
An exceedance occurs if the 8-hour average is greater than .084 ppm. However, enforcement of the health-based standard is currently on hold because of legal challenges to Environmental Protection Agency regulations.
Excessive ozone forms on sunny and windless days and can cause respiratory problems, particularly for children, the elderly and people who suffer from asthma.
Tulsa had declared its third Ozone Alert of the summer Wednesday. To lessen emissions, residents were encouraged to use public transportation or make fewer driving trips during the day, among other voluntary actions.